Hydraulic lift



Nov. 22, 1960 w. E. WEBSTER 2,961,059

HYDRAULIC LIFT Filed April 4, 1957 2 Sheets-Sheet 1 q l-f 20 315.1

INVENTOR. WflEFEA/f. W655 T 55 BY gay JIE. 2 M W H/S a T 7'0ENEYS Nov. 22, 1960 w. E. WEBSTER HYDRAULIC LIFT 2 Sheets-Sheet 2 Filed April 4, 1957 mm mm vIn.

INVENTOR. WflEE'NE. WEBSTE E United States Patent 9 HYDRAULIC LIFI' Warren E. Webster, Dayton, Ohio, assignor to The Joyce-CridJand Company, a corporation of Ohio Filed Apr. 4, 1957, Ser. No. 650,680

Claims. (Cl. 187-8.62)

This invention relates to a hydraulic lift for automotive vehicles and the like, and more particularly to a lift assembly operating from a recess in a floor and so designed that the recess is at all times covered to insure maximum utilization of the floor space and maximum safety to workmen, however, the invention is not necessarily so limited.

An object of this invention is to provide a lift assembly operating from a recess in a floor and having an idle position flush with the floor so as to not interfere with normal use of the floor, wherein said assembly includes a sub-flooring for covering the recess when the lift structure is in an elevated position.

Another object of this invention is to provide, in a lift assembly operable from a recess in a floor and including a sub-flooring for covering the recess, means responsive to vertical movement of the lift structure for accurately and positively positioning the sub-flooring, such that the recess in the floor remains covered whether the lift is in the elevated or the idle position.

Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.

In the drawings,

Figure 1 is a fragmentary, perspective view of the assembly of this invention, the lift structure being illus trated in an elevated position.

V Figure 2 is a fragmentary, perspective view of' the assembly of Figure 1 with the lift structure lowered 'to an idle position.

Figure 3 is an enlarged fragmentary sectional view, taken substantially along the section line 3--3 of Figure 1.

Figure 4 is an enlarged fragmentary sectional view, taken substantially along the section line 44 of Figure 3. Figure 5 is an enlarged plan view of the lift assembly in the idle position, with parts broken away. I

1 Figure 6 is an enlarged side elevational view of the lift assembly in the position of Figure 5, with parts shown in section.

Figure 7 is a greatly enlarged section view, taken substantially along the section line 77 of Figure 5.

' Referring to the drawings in detail, the lift assembly illustrated includes a pair of parallel frame members or lifting rails 10 rigidly secured to hydraulic pistons 12, the latter being employed in combination with a suitable hydraulic power supply, not shown, for lifting the frame members 10. i The frame members 10 are designed to engage the underside, preferably the frame, of automotive vehicles and the like. A wheel locator 11 is positioned in predetermined spaced relation to the lift structure to facilitate positioning of vehicles over the frame members 10 for proper operation of the lift assembly. That is, the vehicle is properly located when one wheel thereof is seated in the wheel locator 11.

Extending parallel to the vertical pistons 12 are vertically movable safety posts 14, engaging the frame members 10 and which serve to prevent rotation of the pistons 12, such that the frame members 10 remain always parallel.

A pinion assembly, not shown, housed under a plate 16 spanning the posts 14 engages racks, not shown, carried by the posts 14 for synchronizing the operation of the pistons 12, such that the frame members 10 remain always at the same elevation. This rack and pinion assembly may be substantially as disclosed in application Serial No. 454,890, filed September 9, 1954, now Patent No. 2,849,084, by Ion V. K. Hott et al. and entitled Flush Floor Mounted Safety Latch for Hydraulic Lift.

.As best seen in Figure 2, the lift assembly operates out of parallel recesses 18 in a floor 20. Where the floor 20 is concrete, as illustrated, the recesses 18 are preferably lined with metallic T rails 21. The lift assembly is designed to operate from an idle position flush with the floor, as illustrated in Figure 2, and elevated positions. This allows for maximum utilization of the floor space when the lift assembly is idle. That is, the frame members 10 become, for all practical purposes, a part of the floor 20.

Upon elevation of the frame members 10, sub-flooring plates 22 are positioned flush with the recesses 18, such that at all times the recesses 18 are covered. These plates provide maximum safety for workmen working about the lift assembly and further aid materially in reducing any accumulation of debris in the recesses 18. The mechanism for positioning the plates 22 is as follows.

Referring to Figure 6 of the drawings, parallel I-beams 24, extending transversely of the recesses 18, are positioned one near each end of each recess. These I-beams 24 support spaced journal blocks 26, which in turn, sup port a rotatably mounted shaft 28. Splined to each shaft 28 are spaced cam supports 30 having an arcuate oblong shape.

/ The plates 22, comprising the sub-flooring for the lift assembly, rest upon these cam supports 30, there being one set of cam supports 30 in each recess 18. Figure 6 illustrates the cam supports 30 positioned such that their longitudinal axis is parallel to the plane of the plate supported thereby. In this position, the plate 22 is spaced below the level of the floor 20 to permit movement of the frame members 10 to a position flush with the floor 20. By a mechanism to be described in detail subsequently, the cam elements 30 may be pivoted 90 to the position illustrated in Figure 3 in response to upward movement of the frame members 10, so as to drive the plates 22 upwardly in the recesses 18 to a position flush with the floor 20. It is to be understood that in the lift assembly herein disclosed, duplicate assemblies are employed for positioning the separate plates 22 associated with the lift assembly.

The mechanism for positioning the cam supports 30 is as follows. A pair of spaced journals 32 are mounted upon a supporting plate 34 positioned within each recess 18 between the cylinder 12 and the safety post 14 associated with each frame member 10 of the lift assembly. These journals 32 support a transversely extending shaft 36 fixedly carrying an arm 38, best seen in Figure 7, which supports a cam follower wheel 40 in spaced parallel relation to the shaft 36. The cam follower wheel 48 is adapted to be engaged by a cam element 42 carried by the adjacent frame member 10. This cam element 42, which is shown in detail in Figure 7, is positioned to project through an aperture 44, best seen in Figure l, in the plate 22.

The cam element 42 is provided with a diagonally ex{ tending slot for receiving the cam follower wheel 40. As:

best illustrated in Figure 7, one surface 48 facing the" member to drive the cam follower wheel 40 to the right, as viewed in Figure 7, so as to rotate the shaft 36 associated therewith in the clockwise direction. Conversely, upon upward movementofthe frame member 10, a surface 50 of the cam element '42. engages the cam follower wheel 40* to return the shaft 36 in the counterclockwise direction.

This rotation imparted to the shaft 36 by the interaction between the cam element 42 and the cam follower wheel 40 is transmitted through arms 52, shafts 54 and 56, and arms 58 to the shafts 28 carrying the cam supports 30. The arms 52 splined to the shaft 36 are longer than the arms 58 splined to the shafts 28, such that a relatively small rotation to the shaft 36 may be amplified to a full one-quarter turn of the shaft 28. As best seen in Figure 6, the shafts 54 and 56 are provided with adjustable fittings 6i and 62,. such that the length of these shafts may be adjusted so as to properly synchronize the movement of the cam supports 30 at the opposite ends of the recesses 18.

Withreference to Figure 6, the operation of the assembly for positioning the plates 22 is as follows. Initially, the frame members 10 may be in the idle position flush with the fioor 20. As the frame members 10 are elevated by the pistons 12, the cam elements 42 carried by the frame members 10, coact with the cam follower wheels 49 to rotate the shafts 36 in the counterclockwise direction, thereby rotating the arms 52 splined to the shafts 36 in the counterclockwise direction. With rotation of the arms 52 in the counterclockwise direction, the cam supports 36 splined to the shafts 28 are rotated in the clockwise direction to elevate the plates 22 to a position flush with the fioor 20. The shape of the cam supports 30 is correlated to the shape of the slotted portions of the cam elements 42, such that the plates 22 will be driven upwardly at a rate less than the rate of the upward movement of the frame members 10, thus insuring that there will be no binding between the frame members 10 and the plates 22.

It is to be noted, as shown in Figure 3, that upon the plates 22 being elevated to the position flush with the floor 2a, the cam sup-ports 30 engage the plates 22 in a two point contact, the points of contact being provided by spaced feet 70 integral with the cam supports 30'. This insures that regardless of the weight placed upon the plates 22, there will be no tendency on the part of the plates 22 to impart rotation to the cam supports 30. This further insures that the shafts 36 associated with the cam follower wheels 49 will'remain in their extreme counterclockwise positions.

Upon subsequent 'lowering of the frame members 10, the cam elements 42 carried thereby, will reengage the cam follower wheels 49, in that the position of these cam follower wheels does not change while the lift structure is in the elevated position. Upon interengagement between the cam elements 42 and the cam follower wheels 40 as the frame members 10 move downwardly, the shafts 36 are driven in a clockwise direction, as viewed in Figure 6, to drive the cam supports 30 in the counterclockwise di-rection, as viewed in Figure 6, to lower the plates 22 in advance of the approaclr'ng frame members 10. As best seen in Figure 7, the slotted portions of the cam elements 42 each terminate in a vertically extending slot 64 enabling accurate positioning of the frame members 10 flush with the floor as without interference with the mechanism for positioning the plates 22.

As illustrated in Figures 3 and 4, suitable brackets 66 may be secured to the T-rails 21 lining the recesses 18 for guiding the plates 22 vertically in the recesses 18. Further, transversely extending angle bars 68 may be securedto the opposite-ends of the plates 22. to provide 'means for limiting the upward movement of the plates plates 22 and frame members 10 are provided with textured or roughened surfaces to reduce the hazard of slipping to workmen.

While the present invention has been applied to a lift assembly including two separately but synchronously driven frame members 10, it is to be understood that this invention may be readily applied to many other forms of lifts including the standard single piston X-frame and H-frame lifts.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. In a lift assembly including a frame for engaging the underside of a vehicle, the lift assembly being adapted to move vertically from a floor provided with a recess for receiving the frame, and means for moving said frame vertically between raised positions and an extreme lowered position within said recess flush with said floor, the improvement including a sub-flooring mounted for vertical movement within said recess, first cam means pivotally mounted within said recess for supporting said sub-flooring, said first cam means having two positions, a first posi' tion supporting said sub-flooring in an elevated position flush with said floor and a second position'supporting said sub-flooring in a lowered position below the floor level, second cam means secured to said frame, and cam follower means mounted within said recess below'said subflooring engageable. with said second cam means when said frame is in a lowered position for actuating said first cam means between said first and second positions in response to vertical movement of said frame, said sub-flooring having an aperture therein permitting interengagement between said second cam means and said cam follower means.

2. The improvement according to claim l'wherein said cam follower means includes a horizontal shaft mounted for rotation in said recess below said sub-flooring, a cam follower wheel, means fixedly supporting said cam fol-. lower wheel in spaced relation to said shaft whereby said cam follower wheel rotates said shaft up'on engage ment with said second cam means, and means responsive to rotation of said shaft for actuating said first cam means between the two positions thereof,said second cam means including a cam element carried 'by said frame adapted to project through the opening in said sub-flooring, said cam element having a first cam surface engagew able with said follower wheel to rotate said shaft in one direction upon movement of said frame upwardly and a second cam surface parallel to said first camsurface engageable with said cam follower Wheel torotate-said shaft in the opposite direction upon movement of'fsaid frame downwardly, the construction and arrangement being such that upon upward movement of said frame from the position flush with said floor said'sub fiooring is driven upwardly to a position flush withsaid floor, and upon downward movement of said frame such that said cam follower wheel is engaged-by said cam'element, said sub-flooring is lowered within said'recess to provide clearance for said frame.

3. The improvement according to claim 1 wherein first cam means includes a pivotally mounted arcuate oblong block provided with spaced foot portions adapted to engage and support the sub-flooring in the elevated position.

4. A lift structure for elevating vehicles above a floor, said structure including a frame adapted to engage the under side of a vehicle, means includinga hydraulic piston for moving said frame between raised positions and a lowered Position, said floor having a recess therein dimensioned to receive said frame such that the lowered portion of said frame is flush with said floor, a subflooring dimensioned to fit said recess adapted to move vertically within said recess, said sub-flooring having two positions, a raised position flush with said floor and a lowered position spaced below said floor so as to permit movement of said frame into said recess, and means for moving the sub-flooring between said two positions including a first cam member supporting said flooring, a second cam element carried by said frame, and cam follower means engageable by said second cam element for pivoting said first cam member between two positions, said first cam member, in one position thereof, supporting the sub-flooring in its raised position and, in the other position thereof, supporting the sub-flooring in its lowered position.

5. In a lift assembly including a frame for engaging the under side of a vehicle adapted to move vertically from a fioor provided with a recess for receiving the frame, and means for moving the frame vertically, the improvement including a sub-flooring mounted for vertical movement in said recess and means for elevating the sub-flooring to a position flush with the floor upon upward movement of said frame, said last named means including a cam having an arcuate oblong shape pivotally mounted in supporting relation to said sub-flooring and actuator means for pivoting said cam between substantially vertical and substantially horizontal positions so as to raise and lower said sub-flooring, said cam having spaced foot portions in the end thereof which is uppermost when in the vertical position, said foot portions coacting with said sub-flooring to yieldingly restrain pivotal movement of said cam away from the vertical position.

References Cited in the file of this patent UNITED STATES PATENTS 652,515 Karberg June 26, 1900 2,464,731 Thompson Mar. 15, 1949 2,655,224 Hott Oct. 13, 1953 FOREIGN PATENTS 613,723 Great Britain Dec. 2, 1948 

